Ceilings are sometimes referred to as the 5th wall in a room, and they are not always meant to be painted 'ceiling white'. Though I do like mine to be a shade of white, I usually tint it with a cast of the wall color to soften the contrast. And, if I'm doing a small bathroom with wallpaper that is a texture or has a small repeat, I like to wrap the whole space, ceiling and all.
But lately, I've had the urge to reverse my norm by painting the walls and papering the ceiling instead. Given the right environment, this can be a great look.
I think the best paper for this application would be something that didn't have a direction such as a geometric, trellis or lattice. I also like something that has a little white in it to set off the contrast between the walls, the trim and the pattern. Here are some of my favorites:
Osbourne & Little
Cole & Son (x3)